This invention relates to a textile spinning and/or twisting machines of the type having rows of spindle units adjacent opposite sides thereof, and is more particularly directed to abatement of the noise which tends to be generated during operation of such machines by vibrations emanating from their spindle units.
During operation of textile machines of the aforesaid type, which for convenience will hereinafter be generically referred to as twisting machines, vibrations are produced at the individual spindle units by the rapid rotative movement which the spindle, bearing and/or other components of such units then undergo. When these vibrations are transmitted from the spindle units to other components of the twisting machine, the noise produced by the other components is frequently greater than that emanating from the spindle units themselves. U.S. Pat. No. 3,604,191 recognizes the foregoing problem, and discloses a spindle mounting arrangement whereby the spindle units of a twisting machine are mounted upon a ladder-like structure, having longitudinal members extending substantially the full length of the machine adjacent opposite sides thereof and having a plurality of cross members extending across the full width of the machine and rigidly interconnecting the longitudinal members, which is connected by blocks or pads of resilient vibration-damping material to the machine's frame. Such arrangement lessens the transmission of vibration from the spindle units to the frame components of the twisting machine, and therefore achieves a degree of noise reduction. The thus-realized noise reduction may be significantly offset, however, by the noise produced by the vibrations induced in the ladder-like spindle mounting structure itself. The rigid, essentially-unitary construction of such structure permits the transmission of vibrations from each spindle unit throughout substantially the entire length of the twisting machine along both sides thereof, and throughout the entire width of the machine at a plurality of longitudinally-spaced locations. Even when the vibrations produced by each spindle unit are of a routine nature, the transmission of them through such an extensive system of rigidly interconnected longitudinal and cross members is not desirable from a noise abatement viewpoint. And if the vibrations produced by a spindle unit should be of a type particularly undesirable from such viewpoint, as could be the case due to bearing wear or the like at the unit in question, localization of them is even more desirable. In addition to the fact that the vibrations of each spindle unit are transmitted to and along an extensive path of travel, the vibrations of all the spindle units are transmitted to and along the same, common path of travel. This raises the possibility of the vibrations emanating from each spindle unit being reinforced by the vibrations produced by any one or more of the many other spindle units, even one located at the opposite end and on the opposite side of the machine. Resonance is also more difficult to avoid when a unitary mounting structure is employed. Modification of, for example, the cross-sectional shape of one component of the structure, for the purpose of eliminating a resonance condition thereat, may produce that same condition in other of the structure's components, due to the rigid interconnection therebetween. Additionally, since the lengths of the components of the unitary mounting structure are determined by the length and width of the twisting machine with which the structure is associated, the avoidance of resonance condition by lengthening or shortening individual components is not possible.